The well documented rise in obesity over the past two decades correlates with increased incidence rates of metabolic and cardiovascular disease. In response to the associated reduced life expectancy and expensive health problems the NIH has established an Obesity Research Task Force. The product development proposed in this SBIR application directly addresses the needs outlined in the Task Force's August 2004 Strategic Plan. One of the tenets of the plan is supporting research toward breaking the link between obesity and its related disorders. Increased abdominal adiposity correlates with defects in glucose homeostasis and is associated with decreased insulin sensitivity in peripheral tissue. Skeletal muscle is an important site of insulin-stimulated glucose disposal and is often the site of insulin resistance in obese individuals. To support research in this area, we propose to develop a well characterized, widely commercially available co-culture system of primary human skeletal myocytes and adipocytes. This cell system will allow researchers to investigate the complex interaction between two cell types directly involved in the etiology of Type 2 diabetes and metabolic disease. Zen-Bio has been providing cultured primary human cells commercially to researchers for the past 10 years and has established the expertise required for the completion of this proposal. The focus of the company has been adipocytes, however, scientists at Zen-Bio have expertise in the isolation, expansion, and differentiation of many types of human primary cells, including myoblasts. Phase I of this proposal consists of two aims. Aim I is expected to establish robust human satellite cell isolation, culturing, and myoblast differentiation protocols. Aim II will build on Aim I by optimizing and validating a co-culture system using human adipocytes and human skeletal muscle cells. Aim I will be achieved by systematically modifying existing protocols to suit the needs of a commercial myocyte system. Detailed activity analysis of each cell type in co-culture conditions will aid in optimizing the system in Aim II. Validation of the interaction between the two cell types in co-culture will be assessed by monitoring skeletal muscle cell insulin signal transduction. Phase II of the project consists of three aims. Aim I is to develop the necessary quality control assays for skeletal muscle cells prior to commercialization, Aim II is to develop a suite of skeletal muscle cell based contract assay services suitable for the study of metabolic disease, and Aim III is the establishment of a cell repository containing cultured adipocytes and skeletal muscle cells from the same patient. Multiple product offerings are expected from this proposal: a human skeletal muscle cell system, a co-culture system using adipocytes and skeletal muscle cells, contract assay services, and assay kits for skeletal muscle cells. At the completion of this project, a commercially available, fully validated human skeletal myocyte system, skeletal myocyte / adipocyte co-culture system, and related assay kits will be offered to researchers. The availability of these systems will provide opportunities for new approaches in the investigation of metabolic disease and a unique methodology to examine the complex interaction between these two cell types. [unreadable] [unreadable] [unreadable]